feat: Harbour RTL vs Go math comparison example + analyzer IMPORT fix

- examples/go_math_compare.prg: Side-by-side comparison of
  Harbour RTL (Abs, Sqrt, Round, Int, Max, Min, Log, Exp, Mod)
  vs Go math package (Sin, Cos, Pow, Pi, Floor, Ceil, Hypot, ...)
- Combined usage: normal distribution, compound interest, distance
- Analyzer: recognize IMPORT package names as valid identifiers
- Analyzer: add math RTL functions (ABS, SQRT, etc.) to known list

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/.pdca-status.json

@@ -1,6 +1,6 @@
 {
   "version": "2.0",
-  "lastUpdated": "2026-03-31T01:15:54.989Z",
+  "lastUpdated": "2026-03-31T01:34:48.246Z",
   "activeFeatures": [
     "hbrt",
     "hbrtl",
@@ -253,9 +253,9 @@
       "documents": {},
       "timestamps": {
         "started": "2026-03-30T23:02:20.210Z",
-        "lastUpdated": "2026-03-30T23:04:18.629Z"
+        "lastUpdated": "2026-03-31T01:34:48.246Z"
       },
-      "lastFile": "/mnt/d/charles/five/compiler/analyzer/analyzer_test.go"
+      "lastFile": "/mnt/d/charles/five/compiler/analyzer/analyzer.go"
     }
   },
   "pipeline": {
@@ -266,7 +266,7 @@
   "session": {
     "startedAt": "2026-03-27T06:06:49.620Z",
     "onboardingCompleted": false,
-    "lastActivity": "2026-03-31T01:15:54.989Z"
+    "lastActivity": "2026-03-31T01:34:48.246Z"
   },
   "history": [
     {
@@ -5374,6 +5374,18 @@
       "feature": "hbrt",
       "phase": "do",
       "action": "updated"
+    },
+    {
+      "timestamp": "2026-03-31T01:32:45.214Z",
+      "feature": "analyzer",
+      "phase": "do",
+      "action": "updated"
+    },
+    {
+      "timestamp": "2026-03-31T01:34:48.246Z",
+      "feature": "analyzer",
+      "phase": "do",
+      "action": "updated"
     }
   ]
 }